When 17-year-old Trayvon Martin was shot and killed in Sanford, Florida on February 26th – the result of an apparent confrontation with George Zimmerman, a neighborhood watch volunteer – he was wearing a hooded sweatshirt. Zimmerman told police that he shot the teenager in self-defense, evoking Florida’s Stand Your Ground law, and has not been charged or arrested. But in the weeks since Martin’s tragic death, the hoodie has emerged as a symbol of support for those who believe justice has not been served. We’ve seen Million Hoodie Marches in cities nationwide. We’ve seen congressmen and NBA players don the hoodie in solidarity. Musicians are getting involved, too. Wyclef Jean sported a hoodie on BET’s 106th and Park while speaking about Martin. At their March 29th concert in Florida, the Red Hot Chili Peppers wore hoodies with the words "Ode To Trayvon, Stand What Ground" splashed across the back.

Meanwhile, other public figures have voiced concerns about the hoodie’s rebellious connotations. Fox News commentator Geraldo Rivera cautioned young black and Hispanic men not to wear hoodies, for fear that they could become victims of social profiling and violence. While Rivera missed the mark, he did spark a real debate: what if Martin’s hoodie actually fueled George Zimmerman’s suspicions? And if so, how can an article of clothing so ubiquitous cast such a sinister shadow?

From its association with punk and hip-hop to skater culture, the hoodie has a history of being adopted by youth-driven communities once relegated to the fringes, imbuing it with an iconoclastic, sometimes criminal, subtext. Mainstream fashion may embrace it as practical article of clothing, but it’s never lost that edge.

The hoodie was born of modest origins. Champion Products, which began as the Knickerbocker Knitting Company in 1919, claims to have made the first hooded sweatshirt. Originally a sweater mill, Champion began making sweatshirts in the early 1930s once it developed methods to sew thicker underwear material.

According to Harold Lipson, a former president at Champion who started at the company in 1934, the hood was first added to sweatshirts in order to protect athletes and laborers from the elements. Employees at cold-storage warehouses and tree surgeons working through the winter were calling for a garment that would provide more warmth than their long underwear. Meanwhile Champion was working directly with high schools to determine their apparel needs, eventually making big double-thickness hooded sweatshirts that football and track athletes wore on the sidelines in bad weather.

The hoodie made the leap from practicality to personal style when athletes started to give their track gear to their girlfriends to wear. Just as they are today, high schools were a breeding ground for popular fashion, and soon sportswear caught on as a fashionable style.

Fast forward to the mid-Seventies, when hip-hop culture was developing on the streets of New York City. Eric "Deal" Felisbret, one of the early graffiti writers, recalls the hoodie popping up on the scene around 1974 or 1975. "The people that wore them were all people who were sort of looked up to, in the context of the street," recalls Deal, who says graffiti writers used the hoodie to keep a low profile, and break-dancers wore it "to keep their bodies warm before they hit the floor."

Deal also recalls that the first people he saw wearing the hoodie were a less savory group of characters looming in the background of urban culture: "stick-up-kids." The stick-up-kids were essentially muggers who had good reason to conceal their identities. Picture this archetypical scene from the earliest days of hip-hop: A DJ is spinning two turntables in the park, while an MC rhymes on the mic. A crowd gathers. All the while, says Deal, the stick-up-kids hang back, watching. "[They] might be sort of scheming on somebody within the crowd that has some sort of clothing or a gold chain or something they’re interested in. They’re probably just gonna wear the hood just slightly over their head and so that way, early on, people can’t remember their faces." Even though the stick-up-kids were criminals, they were highly respected by some, says Deal.

Then there were the graffiti artists, who were also engaging in illicit activities by marking up train cars and subway stations and trying to maintain anonymity. The hoodie was popular among them, but it wasn’t just used to duck the police, says graffiti writer Zephyr. "They were inexpensive, wash-and-wear, and had a convenient built in head-warming aspect," Zephyr said. "With the stealth nature of graffiti, I suppose we liked having our faces cloaked or hidden."

Similarly, the formative years of skateboarding are filled with tales of trespass and evasion. In the mid-Seventies, when the waves were bad in Santa Monica, a ragged surf and skate team known as the Z-Boys found the rounded bellies of empty swimming pools to be ideal riding terrain. The only problem was that they were typically unwanted guests. The Z-Boys reinvented skateboarding with an aggressive riding style and their hoodlum mentality rippled through consciousness of the skateboarding world.

In the early Eighties, the dearth of skate parks forced skaters to adapt and skate wherever they could, legal or not. "By being a skater, you were sneaking around and trying to get into parking garages and the hood up was this way of masking your identity," says author and skateboarder Jocko Weyland.

This outlaw attitude grew into a source of pride, and the skate magazine Thrasher (founded in 1981) reinforced it, printing tales of rebellion and writing in a subversive tone. Skaters rejected the mainstream culture that had rejected them. They were outsiders, and they liked it. And the music they gravitated toward was hardcore and punk, from Black Flag and D.O.A to Descendents.

"You have this real hardcore Black Flag kind of punk, largely in California, but out here as well on the East Coast," says David Browne, Rolling Stone contributor and author of the extreme sports book AMPED. "I think that was the first real merger of these two kinds of subcultures. Suddenly you have this darker, more violent subculture merging with the remains of the skateboard crowd. The whole outsider thing really kicked in at that moment."

The Nineties saw the emergence of especially hard-edged gangsta rap, and groups like Wu Tang Clan and Cypress Hill had a pared-down dress code to go along with their gritty attitudes. The cover of the classic 1993 album Enter the Wu-Tang (36 Chambers) is a particularly grim depiction of the hoodie.

Over time, hip-hop, punk, and skate cultures found common ground in the distaste that society had for them. They could all relate to being harassed by the cops and getting hard looks by adults. And so the hoodie was further interwoven with a culture of defiance. Look no further than Odd Future’s skate-hop aesthetic for evidence of this progression.

Clothing designers such as Tommy Hilfiger and Ralph Lauren took note, finding inspiration in the fashion of the streets. They helped bring the hoodie full circle from the high schools to the streets and back again – though this time with a whole lot more cultural baggage.

The same cloaking abilities that took the hoodie from frozen warehouses and sports fields to the closets of the creative underground are today viewed as a threat to the status quo. When a robbery occurs and the description of the perpetrator includes a hoodie, the hoodie gets dragged through the mud. Many high schools and nightclubs have marked it off their dress code.

When LeBron James tweeted apicture of himself and his Miami Heat teammates wearing hoodies on March 23, the players were showing support for the Trayvon Martin cause. But they were also flouting the controversial ban on hoodies that the NBA has maintained since 2005.

When youth culture, urban style, and race are united by a symbolic item of clothing, singling it out can be problematic. It’s very difficult to strike the hoodie from our social fabric without excluding the same cultures that have adopted it.

Graffiti, skateboarding, hardcore punk, and hip-hop sprung from the desires of supposed ne’er-do-wells to change their surroundings into something more bearable. Gloomy train cars became a canvas, broken pavement became a playground, noise and aggression became musical redemption. American society has embraced all this. We’ve absorbed the music and language of hip-hop. Punk music plays in grocery stores. Skateboarding’s sister sport, snowboarding, is now an Olympic event. The hoodie has been there all along. We can’t hope to eliminate it now.